Methods and compositions for targeting proteins across the blood brain barrier

• US 7,981,864 B2
• Filed: 02/19/2008
• Issued: 07/19/2011
• Est. Priority Date: 10/16/2001
• Status: Expired due to Fees

• Current Assignee: Biomarin Pharmaceutical Incorporated (Amgen Inc.)
• Original Assignee: Biomarin Pharmaceutical Incorporated (Amgen Inc.)
• Inventors: LeBowitz, Jonathan
• Primary Examiner(s): Romeo; David S
• Assistant Examiner(s): Gamett; Daniel C
• Application Number:
  US12/033,802
• Publication Number:
  US 20080241118A1
• Time in Patent Office: 1,246 Days
• Field of Search: None
• US Class Current: 514/8.6
• CPC Class Codes: A61K 2300/00 Mixtures or combinations of active ingredients, wherein at least one active ingredient is fully defined in groups A61K31/00 - A61K41/00
• CPC Class Codes: A61K 38/30 Insulin-like growth factors, i.e. somatomedins, e.g. IGF-1, IGF-2 insulin-like growth factor binding protein A61K38/1754
• CPC Class Codes: C07K 2319/00 Fusion polypeptide
• CPC Class Codes: C07K 2319/02 containing a signal sequence
• CPC Class Codes: C07K 2319/50 containing protease site
• CPC Class Codes: C07K 2319/74 containing a fusion for binding to a cell surface receptor

Abstract

Disclosed are methods and compositions for targeting therapeutic proteins to the brain. Methods and compositions of the invention involve associating an IGF moiety with a therapeutic protein in order to target the therapeutic protein to the brain. Soluble fusion proteins that include an IGF targeting moiety are transported to neural tissue in the brain from blood. Methods and compositions of the invention include therapeutic applications for treating lysosomal storage diseases. The invention also provides nucleic acids and cells for expressing IGF fusion proteins.

Claims

1. A targeted therapeutic fusion protein comprising:

a lysosomal enzyme; and

a mutein of human IGF-I having an amino acid sequence at least 80% identical to mature human IGF-I (SEQ ID NO;

1);

wherein the mutein of IGF-I comprises an amino acid substitution selected from the group consisting of leucine at a position corresponding to Tyr⁶⁰, leucine at a position corresponding to Tyr ²⁴, serine at a position corresponding to Phe¹⁶, and lysine at a position corresponding to Glu⁹, or amino acid substitutions at positions corresponding to Arg⁵⁵ and Arg⁵⁶, of mature human IGF-I (SEQ ID NO;

1); and

wherein the mutein binds to the human cation-independent mannose-6-phosphate receptor in a mannose-6-phosphate-independent manner.

2. The targeted therapeutic fusion protein of claim 1, wherein the mutein of human IGF-I comprises an amino acid substitution of leucine at a position corresponding to Tyr⁶⁰ of mature human IGF-I (SEQ ID NO:

1).

3. The targeted therapeutic fusion protein of claim 1, wherein the mutein of human IGF-I comprises an amino acid substitution of leucine at a position corresponding to Tyr²⁴ of mature human IGF-I (SEQ ID NO:

1).

4. The targeted therapeutic fusion protein of claim 1, wherein the mutein of human IGF-I comprises an amino acid substitution of serine at a position corresponding to Phe¹⁶ of mature human IGF-I (SEQ ID NO:

1).

5. The targeted therapeutic fusion protein of claim 1, wherein the mutein of human IGF-I comprises an amino acid substitution of lysine at a position corresponding to Glu⁹ of mature human IGF-I (SEQ ID NO:

1).

6. The targeted therapeutic fusion protein of claim 1, wherein the mutein of human IGF-I comprises amino acid substitutions at positions corresponding to Arg⁵⁵ and Arg⁵⁶ of mature human IGF-I (SEQ ID NO:

1).

8. The targeted therapeutic fusion protein of claim 6, wherein the fusion protein is deglycosylated by periodate treatment.

7. A targeted therapeutic fusion protein comprising:

a lysosomal enzyme; and

a mutein of human IGF-I having an amino acid sequence at least 80% identical to mature human IGF-I (SEQ ID NO;

1);

wherein the mutein binds to the human cation-independent mannose-6-phoshate receptor in a mannose-6-phoshate-independent manner and wherein the fusion protein is deglycosylated.